Referring to FIGS. 1 and 2, a conventional tool holder disclosed in Taiwanese patent No. 1343306 is adapted to removably hold a socket 6 thereon. The conventional tool holder includes a frame body 1, a bottom seat 2 mounted to the frame body 1, a movable seat 3 rotatably mounted on the bottom seat 2, a spring 4 resiliently interconnecting the bottom seat 2 and the movable seat 3, and a ball 5.
The frame body 1 has two spaced-apart abutment walls 101. The bottom seat 2 has a post 201 formed with a cavity 202. The movable seat 3 has a sleeve 301 sleeved on the post 201 and formed with a hole 303, and a disc 305 connected to a bottom end of the sleeve 301 and formed with two protrusions 302. The spring 4 has opposite ends abutting respectively and resiliently against the bottom seat 2 and the disc 305. The ball 5 engages movably the hole 303.
As shown in FIG. 1, when the movable seat 3 is at a position where the protrusions 302 are away from the abutment walls 101, the hole 303 of the sleeve 301 is registered with a shallow portion of the cavity 202 of the post 201, so that a portion of the ball 5 is pushed out of the hole 303 by the post 201 to engage a groove 601 of the socket 6, thereby securing the socket 6 on the conventional tool holder. As shown in FIG. 2, when the movable seat 3 is turned to a position where the protrusions 302 respectively contact the abutment walls 101, the movable seat 3 is simultaneously moved downwardly and the hole 303 of the sleeve 301 is registered with a deep portion of the cavity 202 of the post 201, so that the ball 5 can retract from the hole 303 and be disengaged from the groove 601 of the socket 6, thereby permitting removal of the socket 6 from the conventional tool holder.
However, the conventional tool holder has a relatively complicated structure, and when assembling of the conventional tool holder, the ball 5 has to be placed manually in the hole 303, and the spring 4 has to be placed manually between the bottom seat 2 and the movable seat 3, thereby resulting in a relatively high manufacturing cost.